The present invention generally relates to manufacturing processes and process control technology, and more particularly to a method and system for positioning guide members in a mechanical assembly that is used to dispense various strip materials, such as yarns, strings, tapes, webs, and ribbons, where the guide members are positioned by electromechanical servos (servomechanisms) that are managed by a microcontroller having a user interface.
There are many conventional machines and mechanisms for dispensing strip-or string-like materials such as tapes, webs, ribbons and yarns. These machines typically include a series of rollers and supports or plates that are used to bring different layers of the end product together along an assembly path, or to apply other materials, such as adhesives, to one or more surfaces of the substrate strip material.
In this type of machinery, it is usually important to have a relatively precise positioning of the strip materials that are to be integrated, and to properly align any applicators that coat the substrates with other materials. Guide arms or guide members of varying designs are often employed for this purpose. One laminating machine that changes the position of tape guide arms to vary the position of tape in relationship to the web is shown in U.S. Pat. No. 4,452,837 (Clausen et al.) wherein a plurality of ribbons are fed through a guide member onto a sheet-like web. The guide is a reciprocating bar having eyelets for receiving a plurality of ribbons, and the bar places the ribbons onto the web in a serpentine pattern to provide continuous reinforcement of the substrate in both the machine direction and the transverse direction. The machine uses a ribbon that is pre-coated with a substrate.
U.S. Pat. No. 5,759,339 (Hartman) discloses a machine for adjusting the position of tape dispensing arms between the webs of a laminating machine using a reciprocating belt to change the position of the dispensing arms and a transducer to identify the position of each dispensing arm.
In PCT Application No. WO 88/04272, (Persson) an arrangement is disclosed for applying longitudinally extending tapes to a moving web having a plurality of tape holders and a plurality of tape applicators for guiding the tape into contact with web. The tape applicators are carried by and are capable of being positioned along mutually separate beams of a beam structure that extends transversely to the direction of web travel. The applicators can be adjusted positionally in relation to an applicator-setting beam, which extends transversely to the direction of web movement, and can be locked to this beam in selected positions therealong. The applicator-setting beam is, in turn, carried for longitudinal movement by a stationary carrier beam, which extends parallel with the applicator-setting beam. The applicator-setting beam can also have graduations provided along the length thereof to show the position of the applicators. The applicator-setting beam is moved in relation to the fixed carrier beam by the tape applicators carried thereby, the carriages of the tape applicators being provided to this end with rotatably journalled wheels that support the applicator-setting beam. Longitudinal movement of the applicator-setting beam is effected by means of a threaded spindle that engages a screw-threaded bore in a nut rigidly connected to the applicator-setting beam. The spindle is journalled, but is locked against axial movement in a stationary frame part. The single treaded spindle moves the applicator-setting beam and the tape applicators.
In many of these prior art machines, the position of one or more parts is sensed electronically, and (when the machinery is off-line) a positioning or guide member is moved and adjusted by actuating an electromechanical motor that is coupled to the guide member, i.e., a servo motor or servomechanism. Servomechanisms are used in a wide variety of applications. By using electronic sensors and servos, process controls for these fabrication systems may be automated, at least in part The sensors and servos may be managed by a microcontroller having a user interface.
Allen-Bradley Co. (Rockwell Automation) sells a line of microcontrollers and related products that may be used for industrial automation. To microcontrollers include the family of small programmable controllers available under the trade designation SLC500. These controllers are one of a type of integrated circuit known generally as a programmable logic controller (PLC). PLCs use a plurality of logic elements and associated interconnect resources that are easily programmed by the end-user to implement user-defined logic operations. They can be programmed using a personal computer (PC) or similar workstation, with appropriate software and a device programmer. Therefore, unlike fully-customized (application-specific) integrated circuits that require a protracted layout procedure and an expensive fabrication process to implement a user's logic operation, a PLC may be utilized to implement the logic operation in a relatively quick and inexpensive manner. Once programmed, these controllers can be operated in conjunction with a user interface (display and keyboard) to automate manufacturing processes in a customized manner.
Unfortunately, these automated process controls have proved inadequate for the manufacture of strip materials. Adjustments of positioning in the machinery, such as tape placement, often require stopping the machinery, i.e., interruption of the actual strip fabrication. There is also a great deal of manual involvement required, such as moving final guides for termination of the strip. It would, therefore, be desirable to devise an improved method of automating the positioning of guide arms for mechanical assemblies used to dispense strip materials. It would be further advantageous if the method could be implemented.